Such feed devices for needle looms are to feed a batt of staple fibers or endless fibers coming from a batt laying device in a possibly draft-reduced manner to the first needle row of a needle loom for the subsequent needling operation. Drafts have harmful effects on the batt uniformity and thus on the batt quality. Each draft increases the variation in the mass distribution within the batt. Thick areas remain thick, thin areas are drawn even thinner.
A well known batt feed apparatus consists of an endless base conveyor band, by which the fiber batt is supported, an endless pre-compression conveyor band arranged above the base conveyor band and approaching same in downstream direction and two so-called finger rollers, i.e. supply rollers arranged downstream of said bands and having a plurality of circumferential grooves distributed in longitudinal direction of the rollers, in which resilient rings from plastic material are slidably arranged at which fingers are formed, which extend in tangential direction of the rings in the direction towards the needle loom and thus bridge over the gusset gaps between the roller nip of the pair of finger rollers and the needle loom, more precisely the holding-down appliance of the needle loom and the needle board of the needle loom, so that the fiber batt slides through these fingers in a compressed condition without suffering considerable drafts. A similar gusset gap bridge-over formed by wires which extend through circumferential grooves in the supply rollers is disclosed in U.S. Pat. No. 3,621,540.
These devices for feeding a fiber batt, however, have the disadvantage, that between the pre-compression device, which is usually formed of said two approaching endless conveyor bands, which are running over reversing rollers, as described above, and the finger rollers, upper and lower gusset gaps remain which have an essentially triangular cross-section and which are not bridged-over and into which the bulky fiber batt bulges in and thereby affect the fiber batt advance to the needle loom. The fiber batt elastically widened into said gusset gaps must be drawn out of them, which results in the known adverse drafts.
To overcome this situation, it is already known to bridge-over the lower gusset gap between the base conveyor band running around a respective reversing roller, and the lower finger roller, by a transmission roller of a smaller diameter which is disposed in said lower gusset gap and essentially fills it. This transmission roller simply leans on the base conveyor band and the lower finger roller under friction and is supported thereby at its total length, so that it cannot bend through. Said transmission roller is preferably driven individually, in order to release the fiber batt from the base conveyor band on its path from the base conveyor band to the lower finger roller and to transmit it to the latter. My co-pending patent application mentioned above offers a solution for bridging-over the upper gusset gap between the pre-compression conveyor band and the upper finger roller.